CDDN® — Certified Developmental Disabilities
Nurse Exam 2026–2027 | Comprehensive 100-
Question Practice Test with Answers &
Rationales| Pdf Access Already Graded A+.
SECTION 1: FOUNDATIONS OF DEVELOPMENTAL DISABILITIES NURSING (Questions 1–15)
1. Developmental disability is best defined as:
A. A condition that only affects learning
B. A physical disability acquired after age 21
C. A severe, chronic disability originating before age 22
D. A temporary cognitive delay
Answer: C) A severe, chronic disability originating before age 22
Rationale: Developmental disabilities are severe, chronic conditions that begin before age 22
and cause functional limitations in major life activities. They are not temporary, do not solely
affect learning, and originate in early development .
2. Which condition is considered a developmental disability?
A. Alzheimer's disease
B. Spinal cord injury at age 45
C. Cerebral palsy
D. Parkinson's disease
Answer: C) Cerebral palsy
Rationale: Cerebral palsy originates in early development and causes long-term functional
impairment. Alzheimer's, Parkinson's, and adult-onset spinal cord injuries are not
developmental disabilities as they occur after the developmental period .
,3. The primary role of the CDDN is to:
A. Provide psychiatric counseling
B. Coordinate medical, behavioral, and social care
C. Prescribe medications
D. Perform physical therapy
Answer: B) Coordinate medical, behavioral, and social care
Rationale: The CDDN integrates healthcare across disciplines to support individuals with
developmental disabilities. This includes coordination of medical, behavioral, and social care
services .
4. Intellectual disability is diagnosed based on:
A. IQ score only
B. Adaptive functioning only
C. IQ, adaptive functioning, and onset before age 18
D. School performance
Answer: C) IQ, adaptive functioning, and onset before age 18
Rationale: Intellectual disability involves deficits in both intellectual functioning (IQ
approximately 70 or below) and adaptive behavior, with onset during the developmental period
(before age 18) .
5. Which ethical principle emphasizes promoting the patient's best interest?
A. Autonomy
B. Fidelity
C. Beneficence
D. Justice
Answer: C) Beneficence
Rationale: Beneficence guides nurses to act for the good of patients, balancing benefits and
burdens in care decisions. It is a foundational ethical principle in developmental disabilities
nursing .
6. Which legislative act ensured the rights of individuals with disabilities to education and
related services?
,A. Americans with Disabilities Act (ADA) of 1990
B. Education for All Handicapped Children Act (1975)
C. Rehabilitation Act (1973) – Section 504
D. HIPAA (1996)
Answer: B) Education for All Handicapped Children Act (1975)
Rationale: The 1975 Act—now known as IDEA (Individuals with Disabilities Education Act)—
mandated free appropriate public education (FAPE) and individualized education plans (IEPs) for
children with disabilities .
7. The most important principle in developmental disabilities nursing is:
A. Medical control
B. Institutional care
C. Person-centered care
D. Cost containment
Answer: C) Person-centered care
Rationale: Care must be individualized, respecting preferences, strengths, and autonomy.
Person-centered care is the foundation of developmental disabilities nursing practice .
8. A child with Down syndrome has a chromosomal pattern of:
A. Trisomy 13
B. Trisomy 18
C. Trisomy 21
D. XYY syndrome
Answer: C) Trisomy 21
Rationale: Down syndrome is caused by an extra copy of chromosome 21 (trisomy 21), leading
to characteristic physical and cognitive features. Trisomy 13 and 18 are different genetic
conditions with more severe prognoses .
9. The most common inherited cause of intellectual disability is:
A. Down syndrome
B. Fragile X syndrome
, C. Cerebral palsy
D. Fetal alcohol syndrome
Answer: B) Fragile X syndrome
Rationale: Fragile X syndrome is the most common inherited cause of intellectual disability. It is
an X-linked genetic disorder associated with behavioral challenges including self-injury and
social anxiety .
10. Autism Spectrum Disorder is characterized by deficits in:
A. Motor coordination only
B. Social communication and restricted behaviors
C. Intelligence only
D. Speech articulation
Answer: B) Social communication and restricted behaviors
Rationale: ASD includes social communication deficits and restricted, repetitive patterns of
behavior. It does not primarily affect motor coordination or intelligence exclusively .
11. Which condition is the MOST common genetic cause of intellectual disability?
A. Fragile X syndrome
B. Down syndrome (trisomy 21)
C. Prader-Willi syndrome
D. Williams syndrome
Answer: B) Down syndrome (trisomy 21)
Rationale: Down syndrome is the most common genetic cause of intellectual disability,
occurring in approximately 1 in 700 live births. Fragile X syndrome is the most common
inherited cause but is less common overall .
12. Adaptive behavior refers to an individual's ability to:
A. Solve abstract problems
B. Manage daily life skills
C. Demonstrate emotional control
D. Maintain physical endurance
Nurse Exam 2026–2027 | Comprehensive 100-
Question Practice Test with Answers &
Rationales| Pdf Access Already Graded A+.
SECTION 1: FOUNDATIONS OF DEVELOPMENTAL DISABILITIES NURSING (Questions 1–15)
1. Developmental disability is best defined as:
A. A condition that only affects learning
B. A physical disability acquired after age 21
C. A severe, chronic disability originating before age 22
D. A temporary cognitive delay
Answer: C) A severe, chronic disability originating before age 22
Rationale: Developmental disabilities are severe, chronic conditions that begin before age 22
and cause functional limitations in major life activities. They are not temporary, do not solely
affect learning, and originate in early development .
2. Which condition is considered a developmental disability?
A. Alzheimer's disease
B. Spinal cord injury at age 45
C. Cerebral palsy
D. Parkinson's disease
Answer: C) Cerebral palsy
Rationale: Cerebral palsy originates in early development and causes long-term functional
impairment. Alzheimer's, Parkinson's, and adult-onset spinal cord injuries are not
developmental disabilities as they occur after the developmental period .
,3. The primary role of the CDDN is to:
A. Provide psychiatric counseling
B. Coordinate medical, behavioral, and social care
C. Prescribe medications
D. Perform physical therapy
Answer: B) Coordinate medical, behavioral, and social care
Rationale: The CDDN integrates healthcare across disciplines to support individuals with
developmental disabilities. This includes coordination of medical, behavioral, and social care
services .
4. Intellectual disability is diagnosed based on:
A. IQ score only
B. Adaptive functioning only
C. IQ, adaptive functioning, and onset before age 18
D. School performance
Answer: C) IQ, adaptive functioning, and onset before age 18
Rationale: Intellectual disability involves deficits in both intellectual functioning (IQ
approximately 70 or below) and adaptive behavior, with onset during the developmental period
(before age 18) .
5. Which ethical principle emphasizes promoting the patient's best interest?
A. Autonomy
B. Fidelity
C. Beneficence
D. Justice
Answer: C) Beneficence
Rationale: Beneficence guides nurses to act for the good of patients, balancing benefits and
burdens in care decisions. It is a foundational ethical principle in developmental disabilities
nursing .
6. Which legislative act ensured the rights of individuals with disabilities to education and
related services?
,A. Americans with Disabilities Act (ADA) of 1990
B. Education for All Handicapped Children Act (1975)
C. Rehabilitation Act (1973) – Section 504
D. HIPAA (1996)
Answer: B) Education for All Handicapped Children Act (1975)
Rationale: The 1975 Act—now known as IDEA (Individuals with Disabilities Education Act)—
mandated free appropriate public education (FAPE) and individualized education plans (IEPs) for
children with disabilities .
7. The most important principle in developmental disabilities nursing is:
A. Medical control
B. Institutional care
C. Person-centered care
D. Cost containment
Answer: C) Person-centered care
Rationale: Care must be individualized, respecting preferences, strengths, and autonomy.
Person-centered care is the foundation of developmental disabilities nursing practice .
8. A child with Down syndrome has a chromosomal pattern of:
A. Trisomy 13
B. Trisomy 18
C. Trisomy 21
D. XYY syndrome
Answer: C) Trisomy 21
Rationale: Down syndrome is caused by an extra copy of chromosome 21 (trisomy 21), leading
to characteristic physical and cognitive features. Trisomy 13 and 18 are different genetic
conditions with more severe prognoses .
9. The most common inherited cause of intellectual disability is:
A. Down syndrome
B. Fragile X syndrome
, C. Cerebral palsy
D. Fetal alcohol syndrome
Answer: B) Fragile X syndrome
Rationale: Fragile X syndrome is the most common inherited cause of intellectual disability. It is
an X-linked genetic disorder associated with behavioral challenges including self-injury and
social anxiety .
10. Autism Spectrum Disorder is characterized by deficits in:
A. Motor coordination only
B. Social communication and restricted behaviors
C. Intelligence only
D. Speech articulation
Answer: B) Social communication and restricted behaviors
Rationale: ASD includes social communication deficits and restricted, repetitive patterns of
behavior. It does not primarily affect motor coordination or intelligence exclusively .
11. Which condition is the MOST common genetic cause of intellectual disability?
A. Fragile X syndrome
B. Down syndrome (trisomy 21)
C. Prader-Willi syndrome
D. Williams syndrome
Answer: B) Down syndrome (trisomy 21)
Rationale: Down syndrome is the most common genetic cause of intellectual disability,
occurring in approximately 1 in 700 live births. Fragile X syndrome is the most common
inherited cause but is less common overall .
12. Adaptive behavior refers to an individual's ability to:
A. Solve abstract problems
B. Manage daily life skills
C. Demonstrate emotional control
D. Maintain physical endurance
